Conventional endoscopes are often supplied with illumination from an external light source. Such light sources generally include high powered lamps, such as xenon lamps. The light sources are generally coupled to the endoscope by means of a detachable waveguide or fiber optic light cable.
An endoscope may be disconnected from the waveguide while still energized by the light source. Light exiting from the waveguide may therefore cause damage if the waveguide is set down without the medical instrument attached. For example, the light may damage operating drapes, a patient's skin, or clothing. Therefore, it is desirable that the light exiting the waveguide be attenuated when the endoscope is determined to be disconnected from the waveguide or fiber optic light cable.
Some devices exist to determine the presence of a light cable on a light source. For example, U.S. Pat. No. 4,356,534 to Hattori discloses a light supply device having a means for detecting a connection between a connector of a cable and a light supply socket using a relay switch operated by a solenoid. U.S. Pat. No. 4,433,675 to Konoshima discloses a light supply apparatus for an endoscope having a detecting section to detect the state of a coupling between a connector and a socket mounted on a housing of the light supply. However, Both Hattori and Konoshima disclose only means for detecting the presence of a connection between a connector and a socket of a light supply. Neither patent discloses a system for detecting the presence of an endoscope on a waveguide.
U.S. Pat. No. 6,110,107 to Bellahsene et al. discloses a fiber optic cable for supplying light to an endoscope and for detecting the presence of the endoscope. However, the specialized cable disclosed in Bellahsene requires electrical conductors running the length of the cable and a switch on the cable's end with a sensor configured to sense the proximity of the endoscope. Therefore, the teachings of Bellahsene may not be used to detect the presence of an endoscope in existing endoscopic systems without using the specialized cable.
It is therefore desired to provide an improved system and method for detecting the presence of an illumination attenuator, such as an endoscope, along an illumination path. It is a further desired to provide such a system that is adaptable to existing illumination attenuator systems without the necessity for a specialized cable or waveguide.